Harness sheave shaft with floating nylon bushing



Oct 31, 1961 F. L. BROOME 3,006,382

HARNESS SHEAVE SHAFT WITH FLOATING NYLON BUSHING Filed March 16, 1959 FIG.1

INVEN TOR. FLOYD L. BROOME BY f Ll ATTORNEY United States Patent 3,006,382 HARNESS SHEAVE SHAFI WITH FLOATING NYLON BUSHING Floyd L. Broome, P.O. Box 698, Atlanta, Ga. Filed Mar. 16, 1959, Ser. No. 799,800 3 Claims. (Cl. 139-84) This invention relates to sheave and shaft assemblies for looms and like textile equipment, and is particularly 0 concerned with the provision of novel and improved antifriction mountings for such sheaves.

In apparatus of the type to which the present invention is particularly adapted, the loom warp threads are controlled by a plurality of harness frames depending in parallel position from individual harness cords which pass over harness sheaves with their outer ends connected with harness jacks whereby the frames are periodically raised and lowered in accordance with the desired pattern of operation of the loom. To those skilled in the art, it will be understood that the effective and efficient operation of the loom is dependent upon the free rotating action of such harness sheaves. The free rotation of the sheaves will of course diminish the load on the loom shedding motion, thus diminishing the required loom power. Freely rotating sheaves also tend to eliminate under and over shots as well as to assist in preventing the throw of the shuttle and decreasing the shuttle knock-outs, thus decreasing warp stops. It will also of course be readily understood that with improvement in the sheave bearing not only is the sheave more freely supported but the sheave may have an increased useful life and lubrication with the attendant danger of material spoilage by contact of lubricating oil therewith may be eliminated.

It is therefore among the primary and general objects of the present invention to provide a novel and improved sheave mounting and bearing assembly for loans.

-A further object of the present invention is to provide a novel sheave and bearing assembly by which freedom of rotation of the sheave is achieved and by which sheave wear is diminished.

Another important object of the present invention is to provide an assembly of the character set forth which will be simple in construction and economical in manufacture of the parts.

A more specific object of the present invention is to provide a novel sheave bearing of such material as to provide resistance to wear and a friction-free mounting to facilitate free running of the sheave.

Also, it is an object of the present invention to provide a sheave bearing assembly by which multiple relative rotation may be achieved between the sheaves and the fixed sheave shaft so as to increase the life of the sheave bearing assembly and to eliminate undue friction.

It is a further object of the invention to provide a sheave assembly by which a construction is achieved providing for the use of sheaves of improved construction particularly adapted to meet the increased demand for economic manufacture.

With these and other objects, features and advantages of the present invention, reference may be had to the following specification taken in conjunction with the accompanying drawings in which:

FIG. 1 is a front elevation of the upper part of a loom showing the harness frames and harness lifting mechanism, together with the improved sheave mounting assembly of the present invention.

FIG. 2 is a side elevation of the sheave assembly of the present invention.

FIG. 3 is a central cross-sectional view through the sheave assembly shown in FIG. 2.

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FIG. 4 is a fragmentary sectional view similar to FIG. 3 and showing a modified form of the assembly of the present invention.

In general terms, that form of the present invention here presented by way of illustrating the inventive concept may be briefly defined as providing a sheave shaft having a diameter substantially reduced from that of the internal bore of the sheaves and upon which there is loosely mounted for rotation with respect thereto a bearing element preferably of friction resistant plastic material such as nylon and which has an external diameter slightly less than the bore of the sheave so as to provide not only for the rotation of the sleeve upon the sheave shaft but for individual rotation of the sheaves on the bearing element. Thus, in the use of nylon for the sleeve, it will be seen that there is provided a sub stantially friction-free bearing of the inner nylon surface of the sleeve upon the normally steel sheave shaft as well as a substantially friction-free loose mounting of the normally wooden sheave on the external nylon surface of the sleeve.

Referring now to the drawings, there is presented in FIG. 1 a fragmentary section of a conventional loom including a portion of the loom frame indicated at 10 with a back arch 11 together with harness jacks 12 and 13 to which the harness cords 14 and 15, respectively, are secured in such vertically adjusted position as to determine the throw of the harness and as dictated by the characteristics of the fabric formed by the loom. The harness cords are extended over the sheave generally indicated by the numeral 16 in FIG. 1, it being understood that sheaves are in multiples, a plurality thereof being mounted on individual sheave shafts 17 which in their present construction are supported by brackets 18 removably and adjustably mounted upon the back arch 11.

With more particular reference to FIGS. 2 and 3 of the drawings, it will be seen that each of the brackets 18 includes a bearing or supporting collar 20 having an internal bore 21 adapted to receive the secured end 22 of the sheave shaft 17. The bearing members 20 are provided with securing set screws or equivalent means 23 for rigidly securing the shaft to the brackets 18. In the present construction of the sheave assembly, that portion of the shaft 17 extending outwardly from the bearing portion 20 of the bracket is of reduced diameter, as indicated at 25, and thereover there is loosely mounted a plurality of cylindrical nylon bearing sleeves 26. The internal diameter of sleeves 26 is slightly in excess of the external diameter of the portion 25 of the shaft 17 so as to provide for freedom of rotary movement of the sleeves 26 upon the shaft 17. In that form of the invention disclosed in FIGS. 2 and 3, the sleeves 26 are of cylindrical form having a combined length slightly in excess of the combined thickness of the multiple sheaves mounted thereon as well as the added combined thickness of sheave spacing washers 33 which may be applied between the sheaves.

The sleeves 26 may be secured against longitudinal sliding motion from the portion 25 of the sheave shaft 17 by a suitably secured washer 28 removably retained by a cotter key 29 seated within an appropriate groove on the outer end of the shaft which is further reduced in diameter to provide a shoulder shown at 25'.

In that form of the invention shown in FIGS. 2 and 3, each sheave includes spaced side flanges 30 forming therebetween a groove 31 for the reception of the harness cords 14, 15 or their equivalent. Each sheave is internally bored as at 32 to receive one of the nylon sleeves 26 therethrough. The diameter of the bore 32 of each sheave is slightly in excess of that of the external diameter of its associated nylon sleeve 26 so as to permit free rotation of the sheaves over the nylon sleeves. As shown at 33 in this assembly, each sheave is spaced from the next adjacent sheave by a washer 33 loosely mounted between the adjacent sheaves so as to straddle the abutment of adjacent sleeves.

In the conventional construction of the looms, the sheaves 16 are formed of Wood and it will here be noted that the contact of the inner bore 32 of the wooden sheaves upon the nylon surface of the sleeves 26 provides for minimum friction and for minimum wear between parts. Similarly, the rotation of the sleeves 26 upon the normally steel sheave shaft 17 also provides a minimum of friction and wear. By this construction, lubricating materials are not required in the assembly 'nor is it necessary to oil the sheaves to induce free rotation and thus endanger the material being formed.

Referring now to FIG. 4 of the drawings, it will be i seen that each sleeve 40 is of short cylindrical form and of a width approximately equal to the width of the bore of the individual sheaves. It will also be noted that in that form of the invention shown in FIG. 4, only the inner sheave 41 is provided with the dual parallel flanges, the remaining sheaves being formed with but a single flange and in each case. the single flange of one sheave cooperates with the outer face of the flange of the next adjacent sheave to provide the proper location and retention of the harness cords on their respective sheaves.

, In considering the foregoing construction, it will of course be understood that the invention is not limited to the specific structural details here presented. Thus the. present inventive concept may be carried out with numerous changes, modifications and the full use of equivalents without departing from the spirit or scope thereof as defined in the appended claims.

I claim:

1. A harness sheave shaft and bearing assembly comprising a shaft bracket having a shaft receiving collar, a steel sheave shaft including an end portion secured within said collar, said shaft including a portionof reduced diameter, a plurality of plastic sleeves having an internal diameter greater than the external diameter of said portion of reduced diameter and of approximately equal overall length thereto mounted thereon, a plurality of wooden sheaves mounted respectively on said sleeves, each having an internal bore of a diameter greater than the external diameter of the sleeve on which it is mounted, each sheave having a pair of spaced peripheral flanges defining a harness cord groove, spacer washers loosely mounted on said sleeves between said sheaves, a washer on the end of said shaft for retaining said sheaves, and means engaging said shaft and retaining said last mentioned washer.

2. A harness sheave shaft and bearing assembly comprising a shaft bracket having a shaft receiving collar, a steel sheave shaft having an end portion secured within said collar, said shaft including a portion of reduced diameter, a plurality of relatively short cylindrical plastic bearing members having an internal bore of greater diameter than the external diameter of said shaft portion of reduced diameter and mounted thereon, a wooden sheave mounted on each of said bearing members, each sheave having a bore of internal diameter greater than the external diameter of said bearing members.

3. A harness sheave shaft and bearing assembly comprising a shaft bracket having a shaft receiving collar, a steel sheave shaft including an end portion secured within said collar, said shaft including a portion of reduced diameter, a plurality of relatively short cylindrical nylon bearing members having an internal bore of greater diameter than the external diameter of said shaft portion of reduced diameter and mounted thereon, a wooden sheave mounted on each of said nylon bearing members, each sheave having a bore of internal diameter greater than the external diameter of said nylon bearing members, an intermediate sheave of said plurality of sheaves having a pair of peripheral flanges and an adjacent sheave having but a single flange.

References Cited in the file of this patent UNITED STATES PATENTS 1,562,644 Jones Nov. 24, 1925 2,119,334 Leflier May 31, 1938 2,315,301 Van Deventer et a1 Mar. 30, 1943 2,487,780 Bacon Nov. 15, 1949 2,696,842 Bullard Dec. 14, 1954 2,760,378 Van Deventer Aug. 28, 1956 

